Rose bushes (Rosa spp.) have a reputation for being finicky plants, but some of this may stem from rose lovers' obsession with perfection—producing the ultimate blooms each season. In reality, roses are pretty tough survivors and will thrive with little to no care. But it certainly is true that roses like a little pampering and will reward your extra efforts with vigorous growth and spectacular flowers. Well-maintained plants also tend to have fewer of the common rose problems, such as mildew or winter damage. For most roses, spring is the most important time for tending to roses, getting them in ship shape for the growing—and blooming—season.
The Rosa genus includes over 100 different species of roses, which are classified as deciduous perennial shrubs. Most rose plants share the familiar general appearance, but their branch structure and size can vary widely, ranging from types with a few stiff, woody canes that get snipped back each year to wild masses of twisting, curling vines. Many roses are fast growers and can reach their full size in a few years. Older, species roses and some climbers tend have the longest life (50 years or more) compared to just 6 to 10 for many modern varieties. New roses are typically planted in spring, when daily temperatures are between 40 and 60 degrees Fahrenheit.
|Botanical Name||Rosa spp.|
|Plant Type||Deciduous shrub|
|Mature Size||6 inches to 20 feet in height and width|
|Sun Exposure||Full sun|
|Soil Type||Loamy, well drained|
|Soil pH||Slightly acidic to neutral (6.5 to 6.8)|
|Bloom Time||Spring, summer, fall|
|Flower Color||White, red, pink, yellow, orange|
|Hardiness Zones||2 to 11, depending on type; USDA|
|Native Area||Europe, Asia, North America|
Plant roses in deep holes partially filled with plenty of amended soil, for drainage, and follow the planting instructions for your rose type. Some recommend forming a cone in the bottom of the planting hole and spreading the roots over the cone. This encourages the roots to grow straight down because deeper is better.
When caring for established plants, start the spring season by removing material used for winter protection, then prune and feed the plants at the appropriate time for the local climate. This is also a good time to apply sprays to get a head start on disease and pest control. After the blooms fade later in the season, deadhead the plants to conserve their energy for more growth and blooms (for repeat-bloomers).
While roses like six hours of sun per day, it does matter what part of the day those six hours come from. Six hours of morning sun is preferable to six hours of afternoon sun, for two reasons. First of all, rose foliage prefers to be dry. The quicker the dampness from the night is burned off the foliage, the less likely disease is to become a factor. Second, afternoon sun is often excessively hot. Roses profit from some afternoon shade.
Roses grow best in loamy, well drained soil with a pH ranging from 6.5 to 6.8. When improving the soil through the use of soil amendments, do not forget to promote drainage by incorporating peat moss. Regardless of the season of the year, apply 2 or 3 inches of mulch over the soil around rose bushes.
Roses need a lot of water, but how much is a lot will vary. Typically, it is best to water roses twice a week—and to water them thoroughly. It's better to water deeply twice per week than to water less deeply more often.
Avoid late-evening watering, which can foster powdery mildew, a very common disease among rose plants. By watering at the end of the day, you are not giving the sunlight a chance to dry things out before night falls. The result is that moisture hangs around all night, creating optimal conditions for powdery mildew.
For the same reason, avoid watering roses from above. Getting the leaves wet will only invite an infestation of powdery mildew. Instead, apply the water at ground level.
Temperature and Humidity
In cold climates, roses may need some winter protection. You can plant them near a house foundation for protection from the coldest wind while having them serve as foundation plantings. In extreme cases, you can use the "Minnesota Tip" winterizing method of bending down the plant's canes so they lie in a trench in the soil, then covering the entire plant with soil and mulch or a pile of leaves for the winter.
There a many different approaches to feeding roses, but a good rule of thumb for beginners is to feed them monthly with a 10-10-10 rose fertilizer. Start feeding them when they are actively growing in spring, coinciding with pruning time.
Among the 100+ species and many more cultivars available, roses are generally grouped into five broad categories:
- Hybrid tea rose bushes are the most popular because they put out a big rose on straight stems.
- Polyanthas produce dense clusters of small flowers on a dwarf rose bush.
- Floribunda rose bushes are a cross between the hybrid teas and the polyanthas.
- Grandifloras produce large rose clusters on long stems.
- Old roses, also called old-fashioned or heirloom roses, were developed prior to 1867; all roses developed later are considered "modern" roses.
- Species or wild roses include ancient varieties that grow naturally across the globe. Many wild roses perform well as landscape plants.
Pruning rose bushes is one of the trickier operations for gardeners new to this aspect of horticulture. The proper type of pruners to use is a set of bypass pruners, not anvil pruners, which can crush the stems.
One aspect of the task that is somewhat debated is whether or not to promote outward-facing shoots when pruning rose bushes. That is, pruning tends to generate a lateral cane at the node below your cut. You can influence the shape of the shrub by making your cut either just above an outward-facing leaf bud or an inward-facing leaf bud. An argument in favor of selecting an outward-facing bud is that you promote growth away from the shrub's center, which facilitates airflow and decreases the chances of problems with mildew. But some experts assert that this practice does not need to be taken as a universal principle.
While some roses do not need pruning, most types benefit from judicious pruning in early spring, before the leaf buds open. The specific time to prune varies by climate. In warm areas where there's little or no freezing in winter, you can prune roses in January. Pruning in warm-winter climates may not be necessary, but it's always a good idea to clean up (removing dead and diseased wood) and thin plants as needed.
Some rose gardeners in warm climates strip all of the leaves from their plants in spring, causing the plants to go dormant for a short time and eliminating leaves troubled by disease or insect eggs. The plants emerge from this forced dormancy refreshed and ready for the growing season. If you try this technique, clean up all of the removed leaves and discard them (don't compost them) to prevent the spread of disease or insects.
If you live in a climate that freezes in winter, wait until April to prune, or until the leaf buds are full but not yet open. Forsythias bloom around this time, so keep an eye out for those bright yellow flowers.
To keep insect pests off your roses, try companion planting with garlic. And once per week, while watering your roses, mix some dishwashing soap into the water and apply this homemade "insecticidal soap" to your bushes (of course, there are also true insecticidal soaps that you can buy).
Growing rose bushes in conditions where adequate spacing is not provided is an open invitation to powdery mildew. Let your roses breathe: Do not plant them too close together. Follow spacing requirements for each particular variety when purchasing rose bushes, as indicated on the plant label.
Another good preventive practice is spraying the plants with lime sulfur in the spring to kill fungus spores (such as black spot) that survived the winter. Spring is also a good time to spray with horticultural oil to destroy insect eggs and larva.